ISSN: 0041-3216

ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 83 Number 2
Research Papers
Cultivar and cultural factors affecting adventitious shoot production on breadfruit root cuttings. (54)
Laura B. Roberts-Nkrumah
The unavailability of adequate quantities of planting material is a serious constraint to the establishment of breadfruit (Artocarpus altilis) orchards. Root cuttings are the most successful method of propagation for seedless varieties, but commonly only one new plant is produced from each cutting. This study was undertaken at The University of the West Indies in Trinidad and Tobago, over a 34-week period, to determine the adventitious shoot production potential of root cuttings and the effects of cultivar and selected cultural factors on shoot production. Root cuttings 5-7 cm in diameter and 15 cm long, of two local cultivars ' 'Yellow' and 'White', were placed in propagating bins and subjected to different levels of exposure, fertilizer, and harvesting methods. More 'Yellow' cuttings (85%) sprouted than 'White' cuttings (67%) by 34 weeks. The percentage of sprouted cuttings declined with increasing exposure, especially for 'White'. 'Yellow' produced more shoots than 'White' (P < 0.001) with the mean shoot production per cutting being 31 and 15, respectively. Shoot production increased with increasing cutting exposure. Shoot harvest was <30% of production and was least (P < 0.001) with the late harvesting methods. Shoot mortality was >30% and increased with fertilizer application and late harvesting. It was concluded that over time, the root cuttings had the ability to produce many adventitious shoots especially with early disease control, no fertilizer, and early shoot harvesting.
Keywords: Exposure; Fertilizer; Harvest method; Shoot harvest; Mortality